Command debate

At work we get into goofy fun little debates about everything, the one this morning is: What is the difference between copy run start and write mem. I am from the standpoint that there is no difference except for the fact write mem is allegedly to be written out of code. My cube mate swears there is a difference and without going into to what he said at this point, I have through the red flag (review). So anyone care to take a stab at this one, but please be ready to backup with documentation.

Well this is true, but basically alot of code has been merged since cisco has aquired many different companies along its journey. I have never known of a difference between the 2, you can use either one to accomplish the same thing and cisco has stated many times get out of the habit of using write mem because it is not going to be supported moving forward. The debate continues strong here in the office and no one has yet come up with an answer.

You know that is my answer as well, though he swears that he read somewhere copy run start does something with other files like vlan.dat and such where write mem only copies the config. I countered that argument but he still swears that theres a difference.

Productive with this one yes as it is work related, but the longest running debate is whether a cheeto is infact a chip. Now how to work that into work productivity is beyond me.

You know that is my answer as well, though he swears that he read somewhere copy run start does something with other files like vlan.dat and such where write mem only copies the config. I countered that argument but he still swears that theres a difference.

Productive with this one yes as it is work related, but the longest running debate is whether a cheeto is infact a chip. Now how to work that into work productivity is beyond me.

The *only* thing that is being written "from" is the dynamic (ie: running) configuration in memory. It's a stupid command (thus Cisco's reason for deprecating it some day....) because it makes no intuitive sense. The source that you're copying from is inferred rather than stated. You *do* save a few keystrokes if you're lazy but that's its sole difference. Also Cisco's own engineers (there's a supertanker that take a long time to change course!) have been doing it this way for years and they are highly resistant to change.

The copy command (thanks Bill Gates) makes more intuitive sense. Just like M$, you're copying from <something> to <something else>
....copy running-config startup-config means your copying the dynamic configuration from RAM to the standard, backup file name "startup-config" which is in NVRAM on an IOS router.

BTW, don't even think of using the write command in a CCNA exam. It's the wrong answer 100% of the time.

Thats always been my take as well though my coworker swears differently. I have challenged him to produce this documentation and he is still looking. Heck im even in support of leaving the write mem for a couple reasons, pix uses it (at least up to 6.x have not used 7 yet so cant say), but most importantly because i have used it for so long its just natural.